The goal of the proposed project is to develop a hybridization-based genotyping assay using dimorphic Alu repeats as genetic markers. The major applications of this genotyping system will be in the fields of paternity testing and forensics. Dimorphic Alu repeats are novel bi-allelic genetic markers that are identical by descent, stable and can be typed by a very simple PCR-based assay. This makes them ideal for human genetic identity testing. Compared to analysis methods using conventional markers such as VNTRs and STRs, the Alu-based genotyping assay on a DNA micro-array format will be a very expedient and cost-effective method. Phase l research will focus on validation of the Alu markers for identity testing applications, probe design for the hybridization-based assay and developing the genotyping assay using multiplexed Alu PCR products. During phase II, emphasis will be shifted to increasing the number of markers in the assay and adapting the assay onto a commercial DNA micro-array platform. PROPOSED COMMERCIAL APPLICATIONS: Current techniques used in the DNA identity testing business rely upon methods such as RFLP which is laborious and time-consuming or multiplex STR analysis which requires expensive kits and instrumentation. The dimorphic Alu markers coupled with a multiplexed genotype analysis on a DNA array will provide a rapid, sensitive and highly cost-effective methodological alternative for DNA identity testing for the numerous private testing laboratories and law enforcement agencies.